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 *  Additional permission under GNU GPL version 3 section 7:
 *
 *  KNIME interoperates with ECLIPSE solely via ECLIPSE's plug-in APIs.
 *  Hence, KNIME and ECLIPSE are both independent programs and are not
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 *  you the additional permission to use and propagate KNIME together with
 *  ECLIPSE with only the license terms in place for ECLIPSE applying to
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 *  Additional permission relating to nodes for KNIME that extend the Node
 *  Extension (and in particular that are based on subclasses of NodeModel,
 *  NodeDialog, and NodeView) and that only interoperate with KNIME through
 *  standard APIs ("Nodes"):
 *  Nodes are deemed to be separate and independent programs and to not be
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 * ---------------------------------------------------------------------
 *
 * History
 *   Oct 10, 2019 (Adrian Nembach, KNIME GmbH, Konstanz, Germany): created
 */
package org.knime.core.data.probability.nominal;

import java.util.LinkedHashSet;

import org.knime.core.data.DataCell;
import org.knime.core.data.meta.DataColumnMetaDataCreator;
import org.knime.core.node.util.CheckUtils;

/**
 * {@link DataColumnMetaDataCreator} for {@link NominalDistributionValueMetaData}.
 * The {@link NominalDistributionValueMetaDataCreator#update(DataCell)} method takes the union
 * of all string values.
 *
 * @author Adrian Nembach, KNIME GmbH, Konstanz, Germany
 * @since 4.1
 */
public final class NominalDistributionValueMetaDataCreator
    implements DataColumnMetaDataCreator<NominalDistributionValueMetaData> {

    private final LinkedHashSet<String> m_values;

    NominalDistributionValueMetaDataCreator() {
        m_values = new LinkedHashSet<>();
    }

    private NominalDistributionValueMetaDataCreator(final LinkedHashSet<String> values) {
        m_values = new LinkedHashSet<>(values);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void update(final DataCell cell) {
        if (cell.isMissing()) {
            return;
        }
        CheckUtils.checkArgument(cell instanceof NominalDistributionValue,
            "The cell %s of type %s does not implement NominalDistributionValue.", cell, cell.getClass());
        final NominalDistributionValue value = (NominalDistributionValue)cell;
        m_values.addAll(value.getKnownValues());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public NominalDistributionValueMetaData create() {
        return new NominalDistributionValueMetaData(m_values);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public NominalDistributionValueMetaDataCreator copy() {
        return new NominalDistributionValueMetaDataCreator(m_values);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public NominalDistributionValueMetaDataCreator
        merge(final DataColumnMetaDataCreator<NominalDistributionValueMetaData> other) {
        CheckUtils.checkArgument(other instanceof NominalDistributionValueMetaDataCreator,
            "Can only merge with NominalDistributionValueMetaDataCreator but received object of type %s.",
            other.getClass().getName());
        final NominalDistributionValueMetaDataCreator otherCreator = (NominalDistributionValueMetaDataCreator)other;
        m_values.addAll(otherCreator.m_values);
        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public NominalDistributionValueMetaDataCreator merge(final NominalDistributionValueMetaData other) {
        other.getValues().forEach(m_values::add);
        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Class<NominalDistributionValueMetaData> getMetaDataClass() {
        return NominalDistributionValueMetaData.class;
    }

}
